Four sprinters broke the national record in the Under-16 boys' 200m final at the 33rd National Junior Athletics Championships on Monday. Delhi sprinter Nisar Ahmed won gold, setting the new record at 21.73 sec. Three other athletes who beat the previous best 22.11 sec were Maharashtra's Karan Hegiste (21.99 sec), Karnataka's Shashikantha (22.00 sec) and Punjab's Satnam Singh (22.04 sec).